1. Field of the Invention
This invention relates to a locking device for an electric connector for use in connection of wiring harness, etc.
2. Description of the Prior Art
Connection of an electric connector is made by engaging and connecting a male connector housing having a plurality of terminal accommodating chambers, which are formed therein and in each of which a metal terminal fitting having an electric wire connected previously therewith is housed, with a female connector housing having also a plurality of terminal accommodating chambers which are formed therein and in each of which a metal terminal fitting having an electric wire connected previously therewith is housed, and then locking them. Since it is substantially necessary to unlock this locking device easily, a great many locking devices for electric connectors have so far been developed.
For example, a female connector housing which is integrally molded of a synthetic resin has locking arms formed on the side walls thereof, and a male connector housing which is molded of the same synthetic resin has projections formed integrally on the side walls thereof and adapted to engage with the locking arms, respectively. Each of the locking arms has a connecting riser portion which connects a locking plate portion having an engaging hole formed therein with an unlocking lever in such a manner that the outer surface of the former is aligned with the inner surface of the latter. In other words, each of the locking arms has a substantially crank-shaped configuration. The connecting riser portion is formed integrally and continuously with the supporting portion of the female connector housing. In the construction of each of the locking arms, the space between the locking plate portion and the female connector housing is kept small to make the entire locking device as compact as possible, whilst the space between the unlocking lever and the female connector housing is kept large to enable the unlocking lever to make a sufficient displacement so as not to interfere with the unlocking operation. Since the connecting riser portion is formed integrally and continuously with the supporting portion as mentioned above, the locking arms formed on the side walls of the female connector housing are allowed to assume a predetermined posture. However, this arrangement was disadvantageous in that, upon making unlocking operation, since the pushing force, that is; the unlocking force applied at a point on the unlocking lever is relaxed or reduced at the supporting portion and then transmitted to a point of application on the locking plate portion, it is required to apply a large pushing force to achieve the unlocking operation.